The efficacy and possible role of epidermal growth factor receptor tyrosine kinase inhibitors in treating early-stage non-small-cell lung cancer have yet to be established. Therefore, we aimed to explore the efficacy and safety of icotinib in completely resected EGFR-mutant stage II-IIIA lung adenocarcinoma patients who underwent standard chemotherapy. This is a randomised, double-blinded, placebo-controlled, multicentre, Phase III trial. A total of 124 patients aged 18-75 years who qualified the inclusion criteria were recruited. These patients were randomised (1:1) to receive either icotinib (125 mg 3 times per day) or placebo (the same dosage and frequency) for 36 months, followed by a further 36 months of observational window. The primary endpoint is disease-free survival (DFS), while the secondary endpoints are overall survival, 3- year and 5-year DFS, safety and tolerability of the medication, and health-related quality-of-life. Analyses will be conducted in a full analysis set and a per-protocol set as well. To our knowledge, the present study is the first randomised, double-blinded, placebo-controlled, multicenter trial designed to explore efficacy and safety of icotonib in this population. The results obtained in the near future may provide potential guidance in clinical practice.